Dinitro-benzotrifluoride compounds



DINITRO-BENZO .UNITED STATES PATENT OFFICE Martin E. Friedrich, Carneys Point, N. J., and Lester E. Schnienp, Wilmington, Dei., assignors to E. I. du Pont de Nemours 8; Company, Wilmington, Del., a corporation oi Delaware No Drawing. Application December 31, 1937,

Serial No. 182,798

12 Claims. (Cl. 260-646) This invention relates to derivatives of benzotrifiuoride and especially to dinitro-benzotrifluorldes and to processes of preparing the same.

It has been found that 'dinitro-amino-benzotrifluorides are valuable intermediates, such as for the production of azo dyes. These amino compounds are conveniently prepared by amination of dinitro-halo-benzotrifiuorides. The compounds of the present invention are intermediates from which the dinitro-amino-benzotrifiuorides may be prepared. They are new compounds and are valuable intermediates.

It is among the objects of the present invention to provide new dinitro-benzotrifluorides. Another object of the invention is to provide new halogen-substituted dintro-benzotrifluorides. Another object of the invention is to provide processes for manufacturing the new compounds. Still other'objects of the invention will be apparent from the following description.

The objects of. the invention are attained in general by dinitrating benzotrifiuoride and halogen-substituted. derivatives thereof in suitable reaction media and under controlled conditions which will produce the desired dinitration.

The invention will be more fully set forth in the following more detailed description which includes examples that are given as illustrative embodiments of the invention and not as limitations thereof.

Example I Ortho. ,-chlor o 'benzot rifiuoride (180.5 parts) was dissolved in zoovp rts of 96% sulfuric acid.

This solution was cooled to 15 C. and agitated.

' A mixture of 130 parts. of 96% sulfuric acid and '10 parts of fuming nitric acid (sp. g. 1.49) was added at such a r'atethat the temperature did not'exceed 25. C. Agitation at C. was continued for two hours after which the reaction mixture was drowned in 800 parts of-ice'. The

mbnonitrdcompound was purified by vacuum distillation. Boiling range 1056 C./l1 mm.

The product "was a mono-nitro-ortho-chloro- Mono ,-,nitro""'-"o' emoro benzotrifiuoride (5o parts) wasidis'so ved in parts of 100% sulfuric L-of fuming sulfuric acid (24% ion was heated to 75 C. and a rts of 100% sulfuric acid and 25 5 C: and stirred at that temperahours.

The temperature was ineoeffc; for a period of 2 hours. The 'reactionimixture was drowned in 800 parts of ice.

I 'Ilhe'ciudeproduct which was precipitated in the mixture as solids was removed by filtration and washed acid-free. The crude product was purified by recrystallizing it from hot methyl alcohol. The purified product melted at 5"l-59- C. and

' consisted essentially of 3.5-dinitro-2-chloro-benzotrifluoride.

3,5-dintro-2-bromo-benzotrifluoride was similarly produced by the nitration of o-bromo-benzotrifluoride.

Example II Ortho chloro benzotrifiuoride (180.5 parts) was dissolved in a mixture of 250 parts of 100% sulfuric acid and 50 parts offuming sulfuric acid (24% $03). This solution was cooled to 20 C. and a mixture of 100 parts of 100% sulfuric acid and parts of fuming nitric acid was (sp. g. 1.49) added, with stirring, at such a rate that the temperature did not exceed 30 C. The reaction mixture was then slowly heated to -80? C. and a mixture of an additional parts of 100% sulfuric acid and 70 parts of fuming nitric acid (sp. g. 1.49) added slowly. The temperature then was increased to 95 C. and the mixture agitated at' that temperature for 10 hours. The temperature then was gradually raised to C. and held 'there for a period of 2 hours. The reaction mixture was drowned in 1500 parts of ice and the product removed by filtration; The crudeproduct was washed acid-free with cold water and redescribed in Examples I and II, benzotrifiuoride yielded 3,5 dinitro benzotrifiuoride, 4 chlorobenzo'trifluoride yielded 3,5-dinitro-4-chloro-benzotrifiuoride and 4-fiuoro-benzotrifluoride yielded 3,5-dinitro-4-fluoro-benzotrifiuoride. Dinitration of 3-chloro, '3-fiuoro or 3-bromo-benzotrifiuoride yielded a mixture of products in which the nitro groups are in the 4,6- and 2,6- positions relative to the CF3 group. In the specification and claims halogen refers to any of the group consisting of chlorine, bromineand fluorine. The halo-benzotrifiuoride starting materials may be substituted by halogen in the ortho, meta or para position to trifiuoro-methyl. As intermediates for dyes the.3,5-dintro-halo-benzotrifluorides are preferred. 3,5-dintro- 2 -chloro-ben'zotrifluoride is especially valuable.

v The substitution of the second nitro group into the benzene nucleus is made in anhydrous sulfuric acid preferably containing an excess' of sulfuric anhydride. Fuming nitric acid is a convenient nitrating agent but nitrate salts and other nitrating agents can be used. It is most convenient to add fuming nitric acid as a mixture of sulfuric and nitric acid which may be made by mixing the acids when cold. The temperature of the final nitration may be varied from 75 C. to 130 C. but temperatures of about 95 .C. are found to give excellent results for the major part of the nitration. At the finish of the dinitration temperatures up to about 130 C. are desirable but heating to such a high temperature is not necessary except for the purpose of better yields.

Example III 3,5-dinitro-2-chloro-benzotrifluoride (46 parts) was dissolved in 150 parts of 90% methyl alcohol. The solution was agitated and heated to 50 C. At this temperature a solution of parts of potassium hydroxide in 50 parts of 90% methyl alcohol was added slowly. The temperature was maintained and agitation continued for 10 hours. Two parts of concentrated sulfuric acid then was added to neutralize the excess potassium hydroxide and the methyl alcohol was removed by distillation. Water was added to the residue and the product extracted from this mixture with ether. The ether was evaporated and the product purified by vacuum distillation.- The product was a viscous oil which boiled at 138-140 C./5 mm. This material was essentially 3,5-dinitro-2-methoxy-benzotrifluoride.

In a similar manner 4-bromo-3,5-dinitrobenzotrifluoride is converted to 4-methoxy-3,5- dinitro-benz0triflu0ride and 3-chloro-4,6-dinitro-benzotrifiuoride yields 3-methoxy-4,6-dinitro-benzotrifluoride.

With the substitution of methyl alcohol by other primary aliphatic alcohols, such as ethyl, propyl or butyl alcohol, the corresponding dinitro-alkoxy benzotrifiuorides are produced. Any alkali metal hydroxide can be used instead of potassium hydroxide.

Since from the foregoing description of the invention it will be apparent to those skilled in the art that various other embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that no limitations are intended except those which are specifically recited in the annexed claims or are imposed by the prior art.

We claim:

1. The benzotrifiuorides represented by the formulae X OF:

OzN CF:

and

in which one Xis hydrogen and the other is one of a group consisting of hydrogen, halogen and alkoxy; and Y is one of a. group consisting of halogen and alkoxy.

2. The 3,5-dinitro-benzotrifiuorides represented by the formula I CF:

in which X is one of the group consisting of halogen, alkoxy and hydrogen.

3. The compounds represented by the formula NO: X

in which one X is halogen and the other X is hydrogen.

4. The compound represented by the formula 5. The compound represented by the formula CFa NO: X

in which X is halogen.

6. The compound represented by the formula dium, heating to about 75 0., adding suificient fuming nitric acid for mono-nitrating said compound and continuing heating to a temperature not in excess of 130 C. until a dinitrated compound is produced.

10. The process which comprises dissolving a mono-nitro-halo-benzotrifluoride in a sulfuric acid medium containing essentially 100% sulfuric acid, heating to about 75 C. and adding sufflcient fuming nitric acid to mono-nitrate the compound, and heating to a temperature between C. and 130 C. until a dinitrated compound is produced.

11. The process which comprises dissolving a mono-nitro-ha1o-benzotrifiuoride in a medium consisting of sulfuric acid and fuming sulfuric acid, heating to 75 C. and adding at least sumcient of a mixture of 100% sulfuric acid and fuming nitric acid to mono-nitrate the compound, and heating to a temperature between 95 C. and C. until a dinitrated compound is produced.

I 12; The process which comprises dissolving a mono-nitro-ortho-halo-benzotrifluoride in a me.- dium consisting of 100% sulfuric acid and fuming sulfuric acid, heating-to 75 C. and, adding at least sufiicient of a. mixture of 100% sulfuric acid and fuming nitric acid to mono-nitrate the compound, and heating to a. temperature be- I tween 95 C. and 130 C. until a. dinitrated como pound is produced.

MARTIN E. FRIEDRICH. LESTER E. SCI-INIEPP. 

